Potential radiosensitizing agents. 4. 2-Nitroimidazole nucleosides

A series of 2-nitroimidazole nucleoside analogues has been synthesized as potential radiosensitizers in an effort to reduce neurotoxicity and increase therapeutic efficacy. The 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl and glucothiopyranosyl analogues of 2-nitroimidazole were synthesized by condensation in the presence of stannic chloride and mercuric cyanide. The deacetylation of these esters was carried out with sodium methoxide at 0 degree C. Condensation of the trimethylsilyl derivative of 2-nitroimidazole with methyl 2-deoxy-2-chloro-4,7,8,9-tetra-O-acetyl-N-acetyl-alpha-D-neuraminate was achieved in the presence of mercuric bromide. These agents were tested for cytotoxicity and radiosensitization in vitro against Chinese hamster (V-79) cells under oxic and hypoxic conditions. The thioglucose and sialic acid analogues were found to be active radiosensitizers.